Hydraulic shear attachments for use with backhoes are well known. Examples of improvements in such devices are set forth in the following U.S. Patents: U.S. Pat. Nos. 4,188,721; 4,198,747; 4,376,340 and 4,403,421.
Hydraulic shear attachments, when mounted on a backhoe or front end loader, are used in dismantling large equipment and in scrap preparation. Hydraulic shear attachments are particularly useful in the demolition of building structures that include or have as part of their support large steel beams or steel reinforced concrete support members. The shear attachment can handle or remove these large metal beams, pipes, tanks and other objects from the structure while working at a safe distance from the point of demolition. Most importantly, the shear means are used in cutting metal beams and pipes in place for faster, safer demolition. This type of shear also is useful in scrap handling applications where mobility of the shear is important.
Because these devices are used to cut large beams, pipes and other metal objects at elevated heights from the ground, mobility is important as well as weight. It is important that the shear attachment be designed and constructed so as not to be excessively heavy thereby diminishing the handling capacity of the overall device. Reduction in weight has resulted in excessive wear of the bearing and pivot used to mount the jaws resulting from the lack of adequate support during operation of the jaw means.
In currently designed shear attachments a fixed lower jaw member and an upper jaw are movable about a pivot point, normally by a hydraulic piston. Because of this movement about the pivot and the lack of lateral support for the jaw assembly, lateral forces which impact upon the upper jaw and the pivot means, particularly when in an elevated position, create excessive wear. This wear results in the breaking down and being out of service for significant periods of time.
Accordingly, it is an object of the present invention to provide a hydraulic shear attachment means having improved wear and strength capabilities. The improvements of the present invention reduce the amount of down time encountered because of the large lateral forces imparted upon the pivot and jaw means of the shear.